The present invention relates to a rotordynamic system, and more particularly to a vertically arranged liquid cooled rotordynamic and motor/generator station.
Industrial pump and compressor systems are common in processed fluid and gas industries such as hydrocarbon and chemical processing, pulp and paper, water treatment, power generation, and sanitary processing industries worldwide.
Conventional pump and compressor systems typically include a multiple of rather large dispersed components. One type of pump and compressor system having multiple stages is driven by an electric motor to produce high pressure at relatively low flows. Other systems utilize a speed increasing gearbox. The multiple stages and/or gearbox allows the usage of a relatively large air cooled motors which operate at a relatively low speed of approximately 3000-3600 rpm. Disadvantageously, multiple stages and/or gearboxes may result in added complexity, reduced reliability and a rather large system. Moreover, the large air cooled motor is typically relatively noisy during operation.
Other types of conventional pump and compressor systems utilize a variable speed drive. The variable speed drive is relatively complex and must be protected from the environmental conditions adjacent the pump. The variable speed drive is therefore remotely located from the pump or compressor in a separate environmentally controlled room. A separate remotely located controller monitors and controls the disbursed system components. Although providing a rather significant practical speed range, the disbursed system complicates installation.
Accordingly, it is desirable to provide an integrated rotordynamic system having a practically unlimited speed range within a small easily transportable package.
The rotordynamic system according to the present invention provides a base mounting a vertical support. A motor, a rotordynamic device and a controller are mounted to the vertical support such that a compact, small footprint system is provided. The motor is mounted in a substantially vertical relationship along the vertical support. The rotordynamic device is a centrifugal pump or compressor operated by the motor to drive a fluid from the input to the output, however, a power recovery turbine driving a generator will also benefit from the present invention.
A liquid cooling system operates to maintain the controller and motor at a desired operating temperature. The liquid cooling system is in heat exchange relationship with an oil system contained within the motor to distribute thermal energy therebetween to further increase thermal control of each. The motor is thereby operable through practically any speed range.
The motor includes a hollow shaft which serves as a xe2x80x9cdynamic oil pump.xe2x80x9d Oil flow from an oil sump is induced in the hollow shaft due to rotation and the passage of vapor through radial feed apertures at the top of the shaft. As the oil rises in the shaft, it removes the thermal energy caused by slip of the induction rotor. The radial feed apertures at the top of the shaft throws cooling fluid out into the multiple passages to direct cooling fluid toward the motor housing on the outside of the stator. The passages are oriented and sized to prevent oil from entering the air gap between the rotor and stator. The oil then flows down under the influence of gravity over a set of cooling coils and drains back into the sump. The coils communicate with the liquid cooling system which is arranged in a heat exchange relationship with the gravity assisted liquid return. Thermal energy within the motor is used to provide preheating of the controller and thereby minimize condensation formation and other environmental irregularities.
The present invention therefore provides an integrated rotordynamic system having a practically unlimited speed range within a small easily transportable package.